ADSL Speed and Performance Part 3 : Traffic and Shaping

Everything you need to understand about traffic shaping and optimization and how usage thresholds affect you.

We've already spoken about the physical limits placed on ADSL connections and we also hopefully have a better understanding of what contention and congestion are.

Now it's time to talk about traffic and shaping aspects that affect Internet speeds. We're also going to give you the low down on understanding acceptable usage policies and how to work with them in this section.

Traffic Overheads

All of the bits and bytes of data that we send flying around the Internet have to have some basic information attached to them to tell them where they are from and where they are going to. We call these bits of extra information that get put onto our traffic wrappers and when we wrap up one type of packet inside another kind of packet we call in encapsulation.

You don't have to know those words, but it is nice to! :)

Just like onions and Shrek data packets can be wrapped up in several layers, especially if they're travelling through several different types of network.

We won't go into huge detail on this but the estimate for the average ADSL packet headed for the Internet is that it is carrying about a 16%-20% overhead. That means that if you for example run a speed test on a 4mbps ADSL line (4096kbps) that a result of around 3.4 – 3.6mbp is actually perfectly normal.

Shaping, or optimizing?

Traffic shaping is probably one of the most misunderstood activities carried out by Internet Service providers. Most users see it in a very negative light, often confuse it with throttling or see it purely as a way that service providers are out to 'spoil their fun'.

Here at MWEB though we prefer to think about this as traffic optimization rather than shaping and use it as a way to ensure that the correct customer activity is given a great experience all the time.

Here's a picture of how traffic optimization works on the MWEB network.